Disazo dyestuffs and a process for their manufacture



Patented Jan. 11,1949

DISAZO DYESTUFFS AND A PROCESS FOR THEIR MANUFACTURE Philippe Grandjean,Basel, Switzerland, assignor to Sandoz Limited,.Basel, Switzerland, aSwiss No Drawing. Application May '26, 1947, Serial No. 750,647' InSwitzerland May 29, 1946 y, 11' J The present invention relates to newdisazo dyestuffs and to a process for their manufacture. It has beenfound that new valuable disazo dyestuffs can be prepared by coupling2-(4faminobenzoylamino) -5-hydroXyn-aphthalene,- 7 sulfonic acid with adiazotised aminoazo dyestufi of the general formula 1 "coon y wherein Xstands for an alkyl, an alkoxy or an acylamino group,Y stands forhydrogen or for an alkyl or an alkoxy group, and wherein Z stands forhydrogen or alkyl.

The aminoazo dyestuffs used as starting products for the presentprocessand corresponding to the above general formula can be prepared bydiazotizing 4-(4'-amino-benzoylamino)-1: hydroxybenzene-2-carboxylicacid or a derivative thereof and coupling the diazotized product with anamine of the benzene series possessing a free position in p-position tothe amino group and a substituent, like an alkyl, alkoxy or acylaminogroup, in meta-position to the said amino group. These amines mayfurther contain a second substituent, like an alkyl or an alkoxy group,in p-position to the first mentioned substituent. Sometimes it may beadvantageous to use, instead of the free amines, theiromega-methanesulfonic acids. In this case the sulfomethyl group must beremoved after formation of the monoazo dyestuffs by heating the samewith an alkali or a diluted acid.

The new dyestufis obtained according to the present process are, in adry state, dark powders easily soluble in water. They dye cotton andregenerated cellulose fibres in red, bordeaux-red, violet or blue shadespossessing good fastness properties to light. They can be diazotized onthe fibre and developed for example. with ,6- naphthol. By thistreatment the shades will generally slightly be modified, but thefastness to water, to washing, perspiration and to crossdyeing aregenerally considerably improved. When after-treated with usualanti-crease agents, the direct and developed dyeingsjshow an unexpectedimprovement of the fastness to light. I

The present invention is characterized by the fact that the aminoazodyestuffs used as starting materials and corresponding to the generalformula given above must contain in o-position to the azo groupidentified by X in the above general formula a substituent differentfrom hydrogen. The new dyestuifs obtainable by the present process aremuch faster to water, to washing and to light than the dyestufis whichcan be obtainedby-diazotization ofthe aminoazo 8 Claims. (crest- 187)dyestuffs corresponding to the above general formula, in which X standsfor hydrogen and Y has the same signification as above, and coupling thesaid diazo compounds with 2-(4-aminobenzoylamino) -'5 hydroxynaphthalene7 sulfonic acid. The action of. the. substituent X on the .fastnessproperties of the new dyestufis could not beexpected and is verysurprising. The new dyestuffs also differ-from the dyestuffs which canbe obtained'according to the process described in French .Patent 882,406by diazotizing the aminoazo dyestuifs'corresponding to the. above citedgeneral formula and coupling the resulting diazo compounds with2-acylamino-5-hydroXynaphthalene-7-sulfonic acid free from diazotizableamino groups, such as for example with2-benzoylamino-5-hydroxynaphthalene-7- sulfonic acid. The fact that thenew dyestuifs can be diazotized on the fibre and developed with,B-naphthol makes it possible to produce dyeings which possess muchbetter fastness properties to wet treatments. Furthermore the directdyeings as well as the developed dyeings of the new dyestuffs are moresuitable for anti-crease finishing insofar as their shades are lessaltered by such a procedure than the analogous dyestuffs known hitherto,while their fastness to light is clearly improved.

The following examples, Without being limitative, illustrate the presentprocess, the parts being by weight.

vErmmple 1 272 parts of4-(4-aminobenzoylamino)-1-hydroxybenzene-2-carboxylic acid arediazotized in the usual manner and introduced into an aqueous solutioncontaining 107 parts of 1-amino-3- methylbenzene and parts ofhydrochloric acid 30 per cent. The aqueous solution is then slowlyneutralized by addition of an aqueous solution of sodium acetate, untilthe coupling is finished, which takes about some hours. Themonoazo'dyestuff thus-obtained is then filtered. For the seconddiazotization it issuspended in water, 69 parts of sodium nitrite areadded thereto and the solution acidulated with hydrochloric acid. Afterthe diazotization is finished, the coupling is carried out in thepresence of sodium carbonate with an aqueous solution of 358 parts of2-(4'-aminobenzoylamino) -5-hydroxynaphthalene-'Y-sulfonic acid'in thepresence of 133 parts of caustic soda lye 30 per cent. The couplingproceeds very rapidly and the disazo dyestuif thus formed isprecipitated, while warm, by means of addition of sodium chloride, thenfiltered and dried.

The new dyestufi is, in the dry state, a dark powder soluble in waterand dyeing cotton and regenerated cellulose fibres in red-bordeauxshades possessing an excellent light-fastness'.

shade becomes slightly modified, while the fast- 7 I mess to the lightWill be improved.

By replacing 1amino-3+irithylbeiizene by 1- amino-3-acetylaminobenzene adyestufl will be obtained, which dyes in reddishbordeaux shadespossessing the same fastness properties. By

using 1-amino-3-methoxybenzene, instead of lamino-B-methylbenzene, adyestufi dyeing in dark bordeaux shades will be obtained.

Example 2 272 parts of 4'-(4--amiiiob'enzoylamino)-lhydroxy-benz'erie=2carboxylic acid are diazotized in the usual manner and coupled in thepresence of sodium acetate with an aqueous solution of 201 parts ofB-methyIaniIine-methane sulfonic acid in the presence of 133 parts ofcaustic soda lye 30 per cent. The coupling is carried "out at roomtemperature and is complete after 2 hours. The sulfo'methyl group isthen removed by heating the dyestufi to 50-60 C. with a solution ofcaustic sodium hydroxide per cent. The aminoazo dyestuff thus obtainedis first precipitated by means of hydrochloric acid, then diazotized andcoupled with 2-(4'-aminobenzoy1- amino)'-5-hydroxynaphthalene-7=sulfonic acid in the manner described inExample 1, whereby an identical disazo dyestuff to that described inExample 1 will be obtained.

Example 3 The diazo compound obtained from,272 parts of i (4'aminobenzoylamino) l-hydroxybenzene-2-carboxylic acid is introduced intoa solution oi 121 parts of 1-amino-2z5-dimethylbenzene, dissolved in 300parts of water and 125 parts of hydrochloric acid 30 per cent. Themixture is then slowly neutralized by means of a sodium acetatesolution, until the coupling has taken place. The aminoazo dyestuff thusobtained'is then filtered off, suspendedin dilute hydrochloric acid anddiazotized by addition of 69 parts of sodium nitrite. After completediazotization the resultant diazo compound is coupled in the presence ofsodium carbonate with 358 parts of 244- aminobenzoylamino)-*5-hyd-roxynaphthalene 7= sulfonic acid in the presence of 133 parts ofcaus tic soda lye 30 per cent. The 'disazo dyestuff thus obtained isprecipitated, while warm, by addition of sodium chloride, filtered anddried. The new dyestuff is a dark powder, soluble in water, dyeingcotton and regenerated cellulose fibres into dark bordeaux shadespossessing excellent fastness properties to light.

By diazotization on the fibre and development with B-naphthol, the shadeof the dyeings will be slightly modified, but their fastness propertiesto water, washing, to perspiration and cross-dyeing are stronglyimproved.

The shades of the direct dyein'gs and of the developed dyeings are alsoslightly modified on after-treatment with anti-creasing agents, whiletheir fastness to light is improved.

Example 4 272 parts of 4-(4-aminobenzoylamino)-1-hydroxybenzene-2-carboxylic acid are diazotized in the usual mannerand coupledwi'th an aqueous solution containing 137 parts of l-aminoZ-methoxy-E-methylbenzene and 125 parts of hydrochloric acid 30 per cent,care being taken that, during the coupling operation, the solution isneutralized by addition of an aqueous solution of sodium acetate. Aftercompletion of the coupliiig operation the aminoazo dyestuff is filtered,suspended in water, then 69 parts of sodium nitrite are added theretoand the diazotization carried out by addition of hydrochloric acid.Whenthe diazoti'zation is finished, this solution is poured into anaqueous solution consisting of 358 parts of.2-(4-aminobenzoylamino)-5-hydroXynaphthalene-7-sulfonic acid containing133 cess of sodium carbonate. The disazo dyestuif tnus'rormed isprecipitated in the warm by means or sodium chloride, filtered anddried.

The new dy'estufi thus obtained is, in the dry state, a dark powderdyeing cotton and regenerated cellulose fibres into violet shades whichare very fast to light.

By diazotization on the fibre and development with ,B-naphthol, the wetfastness properties become strongly increased, whereas the shade changesonly slightly.

By replacing 1-amino-Z-methoXy-S-methylbenzene by1-amino-2:5-dimethoxybenzene a dyestufi dyeing cotton and regeneratedcellulose fibres into blue shades will be obtained. These dyeingspossesssim'ilar fastness properties.

Example '5 286 partsof4-(4-amin0benzoylamino)-1-hydroxybenzene-6-rnethyl-2-carboXylic acid arediazotized in the usual manner and coupled with anaqueous solutioncontaining 107 partsof 1 amino 3-methylbenzene and 125 part's'ofhydrochloric acid per cent. The couplln'gjsolution is slowlyneutralizedwith anaqueous solution'of I Z X wherein X stands for amember selected from the group consisting of alkyl. alkoxy andac'ylainino, Y stands for a member selected from .the group consistingof hydrogen, alkyl and alkoxy andZ stands for a member of thegroupconsisting of hydrogen and alkyl. i 2. A process for the manufacture ofa disazo dyestuft comprising the step-of coupling one molecule of 2-(4''aminobenzo'ylainino) 5 hydroxynaphthalenei'l-sulfoni'c acid with onemolecule of a diazotized monoa'zo dyestufiof theformula icon A processtor the manufacture "of a disa zo dy'estufi comprising the step ofcoupling one molecule, of2-(4-aminobenzoylamlno)-5-hydroxynaphthalene-T-sultonic acid with onemolecule of a diazotized monoazo dyestuff of the formula I OOOH 1m 1 4.A process for the manufacture of a disazo 011 I HO NH-O 0ON=N-QN=N- mnols- NH 6 dyestufi comprising the. step 01 coupling one molecule of2-(4'-aminobenzoylamino)-5-hydroxynaphthalene-7-sulfon1c 'acid with onemolecule of a. diazotized monoazo dyestuff of the for- 5 mule.

5. A disazo dyestuff of the formula,

wherein X stands for a member selected from the 25 group consisting ofalkyl, alkoxy and acylamino,

Y stands for a member selected from the group consisting of hydrogen,alkyl and alkoxy and Z stands for a member of the group consisting ofhydrogen and alkyl.

6. The disazo dyestuff of the formula.

7. The disazo dyestufl of the formula,

OH I H: HOsS- NH 8. The disazo dyestuff o! the formula OCH:

PHILIPPE GRANDJEAN.

(References on following page) REFERENCES )CI'IQED Number The rallowingrierences are of record inf the gggf gi file of this patent: I v 3 1UNITED STATES PA'TENTS 5 2,228,321 Number Name Date 23323370 1,904,820Brightman Apr. 18, 1933 Certificate of Correction Patent No. 2,458,776.January 11, 1949. PHILIPPE GRAN DJEAN It is hereby certified that errorappears in the printed specification of the above numbered patentrequiring correction as follows:

Column 4, line 49, claim 1, after the Word disazo insert dyestuflcomprising the step of coupling one mote; and that the said LettersPatent should be read with this correction therein that the same mayconform to the record of the case in the Patent Office.

Signed and sealed this 6th day of December, A. D. 1949.

THOMAS F. MURPHY,

Assistant Commissioner of Patents.

